[PATCH 4/5] ARM: BCM5301X: Add DT for Asus RT-N18U

[Uwe Kleine-König]

Hello Rafał,

On Wed, Dec 03, 2014 at 07:01:42AM +0100, Rafał Miłecki wrote:
> On 3 December 2014 at 06:40, Rafał Miłecki <zajec5 at gmail.com> wrote:
> > On 3 December 2014 at 00:19, Hauke Mehrtens <hauke at hauke-m.de> wrote:
> >> On 11/30/2014 06:28 PM, Rafał Miłecki wrote:
> >>> +     compatible = "asus,rt-n18u", "brcm,bcm47081";
> >>
> >> Instead of adding bcm47081 to the core code you can do this:
> >>
> >> compatible = "asus,rt-n18u", "brcm,bcm47081", "brcm,bcm4708";
> >>
> >> If we later need some special handling for bcm47081 we can add this but
> >> the old dts file will still work. This is more relevant if the dts file
> >> is in the boot loader.
> >
> > I don't get it. How should I detect there is no second CPU?
> 
> Or did you mean using fact that currently we don't boot the second
> CPU? I don't think we can do that. We should describe the hardware,
> not drivers/arch capabilities. We shouldn't change DTS after adding
> support for boooting 2nd CPU core.
Adding brcm,bcm4708 to the list of compatibles doesn't imply that there
is a 2nd cpu. The semantic is:

	if (kernel_knows_how_to_handle(asus,rt-n18u))
		handle(as=asus,rt-n18u);
	else if (kernel_knows_how_to_handle(brcm,bcm47081))
		handle(as=brcm,bcm47081);
	else if (kernel_knows_how_to_handle(brcm,bcm4708))
		handle(as=brcm,bcm4708);

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |